1. Field of the Invention
The present invention relates to an X-ray imaging apparatus suitable for X-ray diagnosis of circulatory organs.
2. Description of the Related Art
A conventional X-ray imaging apparatus for circulatory organs will now be described with reference to FIG. 1. FIG. 1 shows schematically a ceiling type circulatory organ diagnosis X-ray imaging apparatus. As shown in FIG. 1, a base 1 is mounted on a ceiling 100. The base 1 is connected to a c-arm apparatus via an intermediate arm 2. Base 1 is extendible in the direction of a double headed arrow Ml. The intermediate arm 2 has a horizontal rotary shaft 2A and is rotatable in the direction of a double-headed arrow M2 in respect of the base 1. The c-arm apparatus 3 has an arm base 3A which is extendible in a horizontal direction, and also has a c-arm 3B which is slidable in the direction of a double-headed arrow M3 via the arm base 3A. One end portion of the c-arm 3B is provided with an X-ray generating unit 3C such as an X-ray tube and a diaphragm device, and the other end portion thereof is provided with an X-ray detection unit 3D such as an image intensifier ("I.I."), an optical system, a TV camera, a film changer fixing member, and a film changer ("F.C." ).
A subject 200 placed on a bed (not shown) is situated between the X-ray generating unit 3C and the X-ray detection unit 3D of the c-arm 3B. Thus, those faces of the subject 200, which look to the X-ray generating unit 3C and the X-ray detection unit 3D can be fluoroscopically diagnosed or photographed.
The c-arm 3B having the X-ray generating unit 3C and X-ray detection unit 3D is situated on the left of the subject 200. This arrangement is generally called "left-offset arrangement."
When the above-described X-ray imaging apparatus is employed, there is a case where a doctor stands on one side of the subject 200 or the top plate, and the doctor performs diagnosis or medical treatment on the subject 200. In such a case, the c-arm apparatus 3 may prevent the doctor from diagnosing the subject, when a certain part of the subject is to be diagnosed for a specific purpose.
When the subject 200 is to be accessed from the right, a left-offset arrangement is suitable; when the subject 200 is to be accessed from the left, a right-offset arrangement is suitable. In particular, the right-offset arrangement is desirable when a catheter is inserted into the left arm of the subject 200.
With the above-described conventional apparatus, however, only the left-offset arrangement is allowed, and the apparatus fails to meet demands for various diagnoses.
On the other hand, this type of X-ray imaging apparatus must be provided with suitable X-ray generating unit 3C or X-ray detection unit 3D, depending on parts to be diagnosed. For example, when the heart is to be diagnosed, a small-diameter (e.g. 9 inches) I.I., if employed as X-ray detection unit 3D, is advantageous in clinical angling, etc.; however, when the legs are to be diagnosed, a large-diameter (e.g. 16 inches) I.I. and F.C. need to be employed for maintaining a wide photographing area.
In the conventional apparatus, however, the c-arm apparatus 3 is provided with only one kind of X-ray generating unit 3C and X-ray detection unit 3D, and demands for various diagnoses are not met.